Using BlueTooth receiver/transmitter for subwoofer

galapogos

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Hi guys,
I'm intending to get a HT system, and due to aesthetics, I'd like to place my sub behind rather than in front. I'm also intending to do away with the RCA wire from the receiver to the sub, and use a BT transmitter/receiver pair. I've used a BT 5.0 aptx receiver before with pretty decent results (no lag), so I'm thinking of getting a transmitter/receiver pair in lieu of RCA wires. Would there be any issues I need to take note of?

Thanks.
 

benedium

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I think should not be a problem even with cheaper transmitter+receiver as long as you recalibrate the HT system to factor in any delay. Not sure if some 3.5mm connections will cause any problem though.
 

galapogos

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Thanks. This was what I got previously, just tested it And it works with no lag even in a different room and through walls, so it looks like it'll work.
 

galapogos

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Haha, yeah I saw that, and that's cheap, but doesn't say anything about the codecs supported. The one I got supports both aptX and aptX LL so lag is minimal.
This is the cheapest 2-in-1 (weird they don't sell just the transmitter by itself) that has explicit aptX LL support.
 

patryn33

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Haha, yeah I saw that, and that's cheap, but doesn't say anything about the codecs supported. The one I got supports both aptX and aptX LL so lag is minimal.
This is the cheapest 2-in-1 (weird they don't sell just the transmitter by itself) that has explicit aptX LL support.
Why u considering codec? I though u booking up Sub? Sub operating freq below 2k, these receivers using 2.4khz band, if it’s Bluetooth or WiFi or some other proprietary methods don’t think I need to care. You only care about interference in this freq band


Few years back Qualcomm needs maker to buy their chip to support APTX. Now not sure, but I know is it cost the company loyalty fee to decode APTX. To encode it’s free, maybe it already cost the company since need to buy Qualcomm chip
 
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galapogos

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Why u considering codec? I though u booking up Sub?
Few years back Qualcomm needs maker to buy their chip to support APTX. Now not sure, but I know is it cost the company loyalty fee to decode APTX. To encode it’s free, maybe it already cost the company since need to buy Qualcomm chip
Sorry, do I not need to look at CODEC if I'm just hooking up a sub? Correct me if I'm wrong, but I thought the transmitter will do an ADC, encode it (with aptX/etc), then sent it over BLE? Then the receiver will decode it, then do a DAC back to RCA connectors?
 

galapogos

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patryn33

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Sorry, do I not need to look at CODEC if I'm just hooking up a sub? Correct me if I'm wrong, but I thought the transmitter will do an ADC, encode it (with aptX/etc), then sent it over BLE? Then the receiver will decode it, then do a DAC back to RCA connectors?
BLE is Bluetooth low energy. Aptx I think works over Bluetooth classic and it’s A2DP profile.

A2D to convert analog signal to digital is must but are they doing over A2DP or SPP. If over SPP, they can ustheir own data method to limit freq band and improve sampling rate with proprietary algo depends on brand.
If system using later method maybe better as they not using it’s resource to do work on freq range subwoofer is not using.
BLE and SPP can send data in any format they choose but SPP can operate at higher bit rate and more reliable.

more expensive unit hope they provide better hardware to provide clean signal to sub. Should have better hardware performance. You need to check teardown review.

cheap units, you have to make sure it really support aptx. Guess you can check with a android device to confirm capability.
 
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galapogos

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BLE is Bluetooth low energy. Aptx I think works over Bluetooth classic and it’s A2DP profile.

A2D to convert analog signal to digital is must but are they doing over A2DP or SPP. If over SPP, they can ustheir own data method to limit freq band and improve sampling rate with proprietary algo depends on brand.
If system using later method maybe better as they not using it’s resource to do work on freq range subwoofer is not using.
BLE and SPP can send data in any format they choose but SPP can operate at higher bit rate and more reliable.

more expensive unit hope they provide better hardware to provide clean signal to sub. Should have better hardware performance. You need to check teardown review.

cheap units, you have to make sure it really support aptx. Guess you can check with a android device to confirm capability.
Thanks for the lesson, I know aptX works as a CODEC over A2DP, but didn't know about proprietary encoding over SPP. But since SPP is proprietary, kinda hard to confirm if the quality is really better right?

How can I confirm aptX with an Android device?
 

wwenze

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How can I confirm aptX with an Android device?

Enable developer mode. It will then show what your current connection is using.

It is also supposed to be able to change it but that's buggy I guess. On my phone it will say it changes to something that is clearly unsupported e.g. LDAC but when refreshing the menu it will change back to the supported and currently used settings.

Another more direct way is to just measure latency since that's what you need.
 

patryn33

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Thanks for the lesson, I know aptX works as a CODEC over A2DP, but didn't know about proprietary encoding over SPP. But since SPP is proprietary, kinda hard to confirm if the quality is really better right?

How can I confirm aptX with an Android device?

if u buy from name brands and sites like audio science review positive it’s fine

If your android device supports aptx you can stream to a Bluetooth receiver to check. If it’s just a transmitter, maybe by pairing the logs on phone will also show.
Follow instructions
https://brouken.com/2018/06/how-to-test-if-bluetooth-headphones-use-aptx-or-other-codec/
however the item u cited it’s a transmitter. U have to connect AVR sub out to it, it will need to pair with a sub which supports BT since there is no receiver.
 

benedium

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I assume TS already knows and implied he planning to get one bluetooth transmitter to connect to avr sub out and one bluetooth receiver to connect to subwoofer lfe/rca.

My first question would be connection consistency as in dropouts. 2nd question is gain/volume range.

I assume latency/delay isn't an issue because the AVR room correction should be recalibrated anyway and the subwoofer distance setting would then automatically be changed accordingly to align with the other speakers.

Hope I did not misunderstand.
 
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wwenze

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In that case, even bigger antenna

H5a5d7733bad34f58b8ee776b58b3115aJ.jpg



Bit of trivia: 2.4Ghz antennae follow standard designs be it for WiFi or BT as long as they are all 2.4GHz. Meaning you can even get those directional antennae if you really need it.
 
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